Computer light adjustment

ABSTRACT

A computing device is disclosed. The computing device includes a light source configured to output light. The computing device also includes a light sensor configured to measure the level of light surrounding the computing device. The computing device further includes a control mechanism operatively coupled to the light source and light sensor and configured to adjust the level of output light based on the measured level of light surrounding the computing device.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of co-pending U.S. patent applicationSer. No. 12/949,563, filed on Nov. 18, 2010, and entitled “COMPUTERLIGHT ADJUSTMENT,” which is a continuation of U.S. patent applicationSer. No. 11/737,121, filed on Apr. 18, 2007, and entitled “COMPUTERLIGHT ADJUSTMENT,” which is a continuation of U.S. patent applicationSer. No. 10/402,311, filed Mar. 26, 2003, and entitled “COMPUTER LIGHTADJUSTMENT”, now U.S. Pat. No. 7,236,154, that, in turn, claims priorityto U.S. Provisional Application No. 60/436,205, filed on Dec. 24, 2002and entitled “COMPUTER LIGHT ADJUSTMENT,” each of which is hereinincorporated by reference in their entirety.

FIELD OF THE INVENTION

The present invention relates generally to computing devices and/orsystems. More particularly, the present invention relates to improvedfeatures for controlling light associated with the computing devicesand/or systems.

DESCRIPTION OF THE RELATED ART

Portable computing devices such as notebook computers generally consistof a lid and a base, each of which carries various components used tooperate the notebook computer. By way of example, the base may include ahard drive, a modem, a processor, a disk drive, memory, a keyboard, atrack pad, buttons and the like, and the lid may include a display suchas a liquid crystal display (LCD). The base may also include a batteryfor supplying power to the components of the notebook computer. Thebattery is often quite small and therefore generally only has enoughpower to keep the notebook computer running for a few hours. As shouldbe appreciated, in order to operate effectively, each component consumessome of the power thereby reducing the life of the battery. One of thebiggest consumers of power is the display.

Displays are configured to give visual feedback to a user. For example,the displays may display textual or graphical information such asgraphical user interface (GUI). Displays typically include controls thatallow a user to adjust characteristics of the display screen such asbrightness. By way of example, the controls may be implemented throughkeys disposed on a keyboard. The user typically adjusts the brightnessby incrementally or continuously holding down the key. The controls mayalso be implemented through buttons or switches located on the outsideof the notebook computer. Some external displays such as those utilizingcathode ray tubes (CRT), as for example televisions and computermonitors, may also include controls that allow a user to adjustcontrast. Moreover, some televisions include control mechanisms thatautomatically adjust the brightness level of the television according tothe ambient light around the television.

Notebook computers also give visual feedback to users via smallindicators positioned on the notebook computer. By way of example, someindicators use light to indicate that a notebook computer is turnedon/off or that the notebook computer is in a sleep mode. External lightsmay be used in some cases to provide light to the keyboard of thenotebook computer so that the keys may be seen in low light conditions.

Although light devices of notebook computers typically work well, thereare continuing efforts to improve their form, feel and functionality.For example, it may be desirable to control the light devices of anotebook computer according to the surroundings and environment in whichthey are used.

SUMMARY OF THE INVENTION

The invention relates, in one embodiment, to a computer system. Thesystem includes a processor configured to execute instructions and tocarry out operations associated with the computer system. The computingdevice also includes an input/output controller operatively coupled tothe processor and configured to control interactions with one or moreinput/output devices that are coupled to the computer system, one ormore light sources configured to emit light around the computer system,a light controller operatively coupled to the processor and configuredto process light information associated with the one or more lightsensors and the one or more light sources, a display device configuredto display text and graphics; a display controller operatively coupledto the processor and configured to process display commands to producetext and graphics on the display device, and a program storage blockoperatively coupled to the processor and configured to store data beingused by the computer system, the program storage block storing anillumination program for controlling how the one or more light sourcesare illuminated, the illumination program containing illuminationprofiles for each of the light sources of the computing system, theillumination profiles describing the relationship between the lightoutput of the one or more light sources and the measured ambient lightlevel, the illumination profiles being accessed through a light controlmenu, which is viewed on the display device as part of a graphical userinterface. By way of example, the computing device may correspond to aportable computing device such as a notebook computer.

The invention relates, in another embodiment, to a computing device. Thecomputer device includes, at least, a first light source capable ofoutputting light in order to illuminate a first component of thecomputing device, a second light source capable of outputting light inorder to illuminate a second component of the computing device, thesecond component being distinct from the first component, a light sensorconfigured to measure the level of light surrounding the computingdevice; and a control mechanism operatively coupled to the first andsecond light sources and the light sensor and configured to adjust thelevel of out put light from the first and second light sources based onthe measured level of light surrounding the computing device and firstand second illumination profiles associated with the first and secondlight sources, the first illumination profile being different than thesecond illumination profile.

The invention relates, in yet another embodiment, to a method ofilluminating multiple light sources associated with a notebook computer.The method is includes at least the following steps: determining theambient light level, automatically adjusting the light intensity of afirst light source of a first component of the notebook computer basedon the ambient light level, automatically adjusting the light intensityof a second light source of a second component of the notebook computerbased on the ambient light level, storing a first illumination profilefor the first light source, the first illumination profile defining arelationship between ambient light levels and the light intensity of thefirst light source, and storing a second illumination profile for thesecond light source, the second illumination profile defining arelationship between the ambient light level and the light intensity ofthe second light source, the second illumination profile being differentthan the first illumination profile. In the described embodiment, thelight intensity of the first light source is adjusted according to thefirst illumination profile and wherein the light intensity of the secondlight source is adjusted according to the second illumination profile.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be readily understood by the following detaileddescription in conjunction with the accompanying drawings, wherein likereference numerals designate like structural elements, and in which:

FIG. 1 is a block diagram of a computing device, in accordance with oneembodiment of the present invention.

FIG. 2 is graphical representation showing light intensity versusambient light level, in accordance with several embodiments of thepresent invention.

FIG. 3 is a block diagram of a computer system, in accordance with oneembodiment of the present invention.

FIG. 4 is a flow diagram of illumination processing, in accordance withone embodiment of the present invention.

FIG. 5 is a diagram of a graphical user interface (GUI), in accordancewith one embodiment of the present invention.

FIGS. 6A-C are graphical representations showing light intensity versusambient light level, in accordance with several embodiments of thepresent invention.

FIG. 7 is a perspective diagram of a portable computer, in accordancewith one embodiment of the invention.

FIG. 8 is a side elevation view, in cross section, of a portablecomputer, in accordance with one embodiment of the present invention.

FIG. 9 is a side elevation view, in cross section, of a portablecomputer, in accordance with an alternate embodiment of the presentinvention.

FIG. 10 is a side elevation view, in cross section, of a portablecomputer, in accordance with an alternate embodiment of the presentinvention.

FIG. 11 is a side elevation view, in cross section, of a portablecomputer, in accordance with an alternate embodiment of the presentinvention.

FIG. 12 is a side elevation view, in cross section, of a portablecomputer, in accordance with an alternate embodiment of the presentinvention.

FIG. 13 is a side elevation view, in cross section, of a back litkeyboard, in accordance with one embodiment of the present invention.

FIG. 14 is an exploded perspective view of a back lit keyboard, inaccordance with one embodiment of the present invention.

FIG. 15 is a broken away side elevation view, in cross section, of aback lit keyboard, in accordance with one embodiment of the presentinvention.

FIG. 16 is a top view, in cross section, of a portable computer, inaccordance with one embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The invention generally pertains to controlling light sources associatedwith various components of a computing device or system. In particular,controlling the intensity of light outputted by the light sources basedon the level of ambient light surrounding the computing device orsystem. One aspect of the invention relates to automatically adjusting alight source associated with a display device according to the ambientlight level. As should be appreciated, in order for the display to beseen properly, the light therefrom generally has to be bright in highambient light and relatively dim in low ambient light (e.g., darkness).Another aspect of the invention relates to automatically adjusting alight source associated with a keyboard according to the ambient lightlevel. As should be appreciated, in order for the keyboard to be seenproperly, the light therefrom generally has to be bright in low ambientlight. In one particular embodiment, the keyboard light comes on in lowambient light thereafter adjusts to the ambient light level and thenautomatically shuts off in brighter ambient light. Yet another aspect ofthe invention relates to automatically adjusting a light sourceassociated with an indicator according to the ambient light level.

The invention is particular suitable for use in portable computers suchas notebook or laptop computers where substantial battery life can besaved by adjusting the intensity of light in order to reduce the powerconsumption of the light sources. The amount saved generally depends onthe ambient light level. By way of example, the life of the battery maybe increased up to 40% when automatically adjusting the light sourcesdescribed above. In addition, the invention provides light in acontrolled manner so that components of the portable computer can beseen properly and clearly. For example, the light may illuminate acomponent such as a keyboard so that it can be used in low lightconditions (e.g., in the dark).

Embodiments of the invention are discussed below with reference to FIGS.1-16. However, those skilled in the art will readily appreciate that thedetailed description given herein with respect to these figures is forexplanatory purposes as the invention extends beyond these limitedembodiments.

FIG. 1 is a block diagram of a computing device 100, in accordance withone embodiment of the present invention. The computing device 100 isgenerally configured to process, send, retrieve and/or store data. Byway of example, the computing device may correspond to desktop computers(both segmented and all-in-one machines), portable computers (e.g.,laptops), handhelds (e.g., media players, personal digital assistantsand mobile phones) or the like. As shown, the computing device 100includes a light source 102 and a light sensor 104, both of which areoperatively coupled to a control mechanism 106. The light source 102,light sensor 104 and control mechanism 106 make up a light adjustmentcircuit that is configured to effect lighting associated with thecomputing device 100 in a non-trivial manner.

The light source 102 is generally configured to output light 108 so thatit can be seen by a user of the computing device 100. For example, thelight source 102 may be used to light up many types of light devicessuch as indicators, displays, keyboards, buttons, connectors and thelike. With regards to indicators, keyboards buttons, and connectors thelight source may correspond to a light emitting diode (LED). Withregards to the display, the light source may correspond to a displaytube (e.g., cathode ray tube) or a display panel such as those used inliquid crystal displays (LCD). The light sensor 106, on the other hand,is configured to receive and measure the level of light 110 thatsurrounds the computing device 100 during use, as for example, lightthat is produced by incandescent, sunlight, fluorescents, and the like.This type of light is sometimes referred to as “ambient light.” By wayof example, the light sensor 106 may correspond to a photodiode,phototransistor, photoresistor or the like. An example of an illuminatedconnector may be found in U.S. Pat. No. 6,357,887, titled “Housing for aComputing Device”, issued Mar. 19, 2002, which is herein incorporated byreference.

Moreover, the control mechanism 104 is generally configured to adjustthe level of the light 108 based on the measured level of the light 110.For example, depending on the light level of light 110, the controlmechanism 106 may increase or reduce the power that is delivered to thelight source 102 thereby effecting the light intensity of the lightsource 102. The intensity of the outputted light 108 is generally set ata level that differentiates it from the ambient light 110, i.e., providesufficient contrast between the light being outputted by the lightsource 102 and the ambient light surrounding the computing device 100.In one particular embodiment, and referring to FIG. 2, the intensity ofthe outputted light 108 is configured to be high in high ambient light110 and low in low ambient light 110. This is typically done so as toallow a user to easily view the outputted light 108 when using thecomputing device 100, i.e., more light is needed when the ambient lightlevel is bright and not as much light is needed when the ambient lightlevel is dark. This is also done to reduce the power consumption of thecomputing device 100 (as some users may leave light devices, i.e.,displays, on maximum brightness). This may be advantageous in portabledevices that include batteries, i.e., reducing the power consumption mayincrease battery life. Although this particular embodiment is shown anddescribed, it should be noted that it is not a limitation and that therelationship between light intensity and ambient light level may varyaccording to the specific needs of each device. For example, in somecases, the intensity of the outputted light may be configured to be lowin high ambient light 110 and high in low ambient light 110 (e.g., thismay allow the light to be seen in darkness). By way of example, theambient light level may range from about 0 lux (e.g., darkness) to about1000 lux (e.g., a very bright room).

The control mechanism 110 may be a dedicated block or it may be a partof the control system that controls other functions of the computingdevice 100. By way of example, it may correspond to a micro controllerand/or a processor.

FIG. 3 is a block diagram of a computer system. 150, in accordance withone embodiment of the present invention. By way of example, the computersystem 150 may correspond to the computing device 100 shown in FIG. 1.The computer system 150 generally includes a processor 152 (e.g., CPU ormicroprocessor) configured to execute instructions and to carry outoperations associated with the computer system 150. For example, usinginstructions retrieved for example from memory, the processor maycontrol the reception and manipulation of input and output data betweencomponents of the computer system 150. In most cases, the processor 152executes instruction under the control of an operating system or othersoftware. The processor can be a single-chip processor or can beimplemented with multiple components.

The computer system 150 also includes an input/output (I/O) controller154 that is operatively coupled to the processor 152. The (I/O)controller 154 may be integrated with the processor 152 or it may be aseparate component as shown. The I/O controller 154 is generallyconfigured to control interactions with one or more I/O devices 1.56that can be coupled to the computer system 150. The I/O controller 154generally operates by exchanging data between the computer system 154and I/0 devices 156 that desire to communicate with the computer system150. In some cases, the I/O devices 156 may be connected to the I/Ocontroller 154 through wired connections such as through wires orcables. In other cases, the I/O devices 156 may be connected to the I/Ocontroller 154 through wireless connections. By way of example, the I/Odevices 156 may be internal or external devices such as hard drives,disk drives (e.g., floppy, CD, DVD, etc.), keyboards, mice, track balls,touch pads, printers, scanners, speakers, video cameras, MP3 players andthe like. The I/O devices 156 may also be network-related devices suchas network cards or modems. In the illustrated embodiment, the I/Odevice 156 is an illuminable keyboard, as for example, a backlitkeyboard.

The computer system 150 also includes a light controller 162 that isoperatively coupled to the processor 152. The light controller 162 maybe integrated with the processor 152 or it may be a separate componentas shown. The light controller 162 is configured to process lightinformation associated with one or more light sensors 164 and one ormore light sources 166. The light sensors 164 are generally configuredto measure the ambient light level surrounding the computer system 150and the light sources 166 are generally configured to emit light. By wayof example, the light sensor may be configured to measure the ambientlight level between about 0 lux (e.g., darkness) to about 1000 lux(e.g., a very bright room). In most cases, the light controller 162operates by exchanging data between the light sensors 164, light sources166 and the processor 152, i.e., the light controller 162 directs themeasured output from the light sensors to the processor 152 and itdirects light instructions from the processor 152 to the one or morelight sources 166. In the illustrated embodiment, the computer systemincludes a pair of the light sensors 164. It is generally believed thatusing multiple light sensors produces a more accurate reading of theambient light surrounding the computer system (e.g., average). It shouldbe noted that two light sensors is not a limitation and that one or morelight sensors may be used.

The light sources may be widely varied. By way of example, the lightsources may be one or more light emitting diodes (LED), light emittingsemiconductor dies, lasers, incandescent light bulbs, fluorescent lightbulbs, neon tubes, liquid crystal displays (LCD), and the like.Furthermore, the location of the light sources may be widely varied. Thelight sources may be located in almost any component of the computersystem 150. For example, the light sources may be contained in one ormore of the I/O devices described above or within a housing of thecomputer system 150, as for example, the housing that contains theprocessor 152. In the illustrated embodiment, a first light source 166Aemits light for lighting up the keyboard 156, and a second light source166B emits light for lighting up an indicator 157 of the computer system150. By way of example, the indicator 157 may be a sleep indicator thatalerts users when the computer system is in a sleep mode. In most cases,the light sources 166A and 166B correspond to LEDs.

The computer system 150 also includes a display controller 168 that isoperatively coupled to the processor 152. The display controller 168 maybe integrated with the processor 152 or it may be a separate componentas shown. The display controller 168 is configured to process displaycommands to produce text and graphics on a display device 170. By way ofexample, the display device 170 may be a monochrome display, colorgraphics adapter (CGA) display, enhanced graphics adapter (EGA) display,variable-graphics-array (VGA) display, super VGA display, liquid crystaldisplay (e.g., active matrix, passive matrix and the like), cathode raytube (CRT), plasma displays and the like. In the illustrated embodiment,the display device corresponds to a liquid crystal display (LCD) thatcontains a light source 172 for delivering light to the LCD. In mostcases, the light source 172 corresponds to a light panel such as afluorescent light panel that emits light behind (and sometimes beside)the remaining layers or panels of the LCD (e.g., polarizing filters,liquid crystal cells, color filters, glass plate).

Although not shown, the computer system 150 may include one or moremedia bays (expansion bays) may be used to receive media bay devices(expansion bay devices) to provide greater resources to the computersystem 150. As examples, the types of devices include a floppy drive, ahard drive, a CD-ROM drive, a DVD drive, or a battery. The media baysare typically externally accessible from to the computer system 150 sothat media bay devices can be easily be inserted into the media bays orremoved from the media bays. The removability of the media bay devicesallows a few media bays to support a variety of different types ofdevices in a flexible manner.

In most cases, the processor 152 together with an operating systemoperates to execute computer code and produce and use data. The computercode and data may reside within a program storage block 176 that isoperatively coupled to the processor 152. Program storage block 176generally provides a place to hold data that is being used by thecomputer system 150. By way of example, the program storage block mayinclude Read-Only Memory (ROM), Random-Access Memory (RAM), hard diskdrive and/or the like. The computer code and data could also reside on aremovable program medium and loaded or installed onto the computersystem when needed. Removable program mediums include, for example,CD-ROM, PC-CARD, floppy disk, magnetic tape, and a network component. Asis generally well known, RAM is used by the processor as a generalstorage area and as scratch-pad memory, and can also be used to storeinput data and processed data. ROM can be used to store instructions orprogram code followed by the processor as well as other data. Floppy andhard disk drives can be used to store various types of data. Floppy diskdrive facilitates transporting such data to other computer systems, andhard disk drives permit fast access to large amounts of stored data.

In one embodiment, program storage block 176 is configured to store anillumination program for controlling how the lights sources, as forexample, the light sources associated with the keyboard 156, indicator157 and the display device 170, are illuminated. The illuminationprogram may contain illumination profiles for each of the light sourcesin the computer system 150, as for example light sources 166A, 166B and172. The illumination profiles generally contain information or tablesthat describe how the light sources change in accordance with someevent. For example, the illumination profiles may describe therelationship between the light output and the ambient light level, i.e.,for a measured ambient light level, the light intensity of the lightsource should be set at a particular level. This information may be usedin the illumination program to control the light sources based on aparticular level of ambient light. The ambient light level may be themeasured light level as for example, the level measured by the lightsensors 164 or it may be some preset value. With regards to the later,the preset value may be some default value based on averages or it maybe a value corresponding to a particular use, i.e., the user may set thevalue based on his/her location (e.g., lots of sunshine, inside a roomusing fluorescents and/or incandescent, complete or partial darkness,and the like).

In one implementation, the illumination profiles may be accessed by auser through a light control menu, which may be viewed on the displaydevice 170 as part of a GUI interface. The light control menu mayinclude light control settings pertaining to the illumination profiles.In fact, the light control menu may serve as a control panel forreviewing and/or customizing the light control settings, i.e., the usermay quickly and conveniently review the light control settings and makechanges thereto. Once changed, the modified light control settings willbe automatically saved and thereby employed to handle futureillumination processing.

FIG. 4 is a flow diagram of illumination processing 200, in accordancewith one embodiment of the present invention. By way of example,illumination processing may be implemented in the computer system ofFIG. 2. Illumination processing generally begins at block 202 where adetermination is made as to whether or not a light feature associatedwith a light source is activated. The light feature is generallyconcerned with how the various light sources of a computer system, asfor example, the keyboard lights 166A, the indicator lights 166B and thedisplay device 172 of FIG. 2, are illuminated. If the light feature isnot activated, then the process flow ends.

If the light feature is activated, then the process flow proceeds toblock 204 where the ambient light level is determined. The ambient lightlevel is an indication of the degree of light to be utilized withillumination processing. In one embodiment, the ambient light level isdetermined by monitoring the output from one or more light sensors, asfor example light sensors 164 in FIG. 2. In another embodiment, theambient light level is determined by referring to user settings. Forexample, a user may enter information about the ambient light level(e.g., working inside, working outside, working in a dark room, workingin a well lit room, etc.). The information may be initiated at start upby the computer system, as for example via a pop up window, or it may beuser initiated via a GUI window that is opened by the user.

Following block 204, the process flow proceeds to block 206 where thelight intensity of the light source is determined based on the ambientlight level. This may be accomplished with a formula, a data table orthe like. For example, the light intensity may be calculated using aformula, which includes the ambient light level as a variable.Additionally, the light intensity may be determined using data tablesthat show a relationship between the ambient light level and theintensity of the outputted light, i.e., once the ambient light level isdetermined, it can be used to look up the appropriate light intensityassociated therewith. The data tables may be found experimentally orthrough simulation or modeling. The formulas and data tables themselvesmay be widely varied. For example, they may be preset or they may bemodifiable.

Following block 206, the process flow proceeds to block 208 where thelight intensity of the light source is set. For example, the powerdelivered to the light source may be adjusted to bring it theappropriate light intensity. After the light intensity has been set, theillumination processing is complete and ends. However, the illuminationprocessing may be repeated at various intervals in case some input haschanged, i.e., check to see if the light feature is still activated orif the data tables have been modified. By way of example, illuminationprocessing may be repeated about 10 times a second, once every twoseconds or somewhere therebetween.

The various aspects of the illumination processing described above canbe used alone or in various combinations. The illumination processing ispreferably implemented by a combination of hardware and software, butcan also be implemented in hardware or software. The illuminationprocessing can also be embodied as computer readable code on a computerreadable medium. The computer readable medium is any data storage devicethat can store data, which can thereafter be read by a computer system.Examples of the computer readable medium include read-only memory,random-access memory, CD-ROMs, DVDs, magnetic tape, optical data storagedevices, and carrier waves. The computer readable medium can also bedistributed over a network coupled computer systems so that the computerreadable code is stored and executed in a distributed fashion.

FIG. 5 is a diagram of a graphical user interface 250 (GUI), inaccordance with one embodiment of the present invention. The GUI 250represents the visual display panel for displaying the light profiles ofone or more light sources on a computer display screen. Through the GUI250, the user may quickly and conveniently review the light settingsassociated with the light source(s) and make changes thereto. The GUI250 serves as a control panel for reviewing and/or customizing the lightoptions associated with the various light sources.

As shown, the GUI 250 includes a window frame 252 that defines a windowor field 254 having contents contained therein. The contents may bewidely varied. The contents may include one or more on screen options,switches, labels, warnings and the like. In the illustrated embodiment,the GUI is dedicated to keyboard illumination and thus the field 254includes an illumination option 256, a light adjustment slider 258, andan ambient light adjustment option 260. The illumination option 256, ifit is enabled, instructs a computer system to illuminate the lightsource when the ambient light level is low. (Sometimes the keyboard doesnot have to be lit). The light adjustment slider 258, on the other hand,gives the user the ability to designate the desired brightness of theillumination provided by the light source. For example, by moving theslider, the user may increase or decrease the level of brightness.Furthermore, the ambient light adjustment option 260, if it is enabled,allows the computer system to automatically adjust the light intensityof the light source based on the ambient light levels. Additionally, avisual indication such as warning window 262 or check mark 264 may beused to inform the user as to which options are selected.

It should be noted that the GUI configuration shown in FIG. 5 is not alimitation and that the configuration may vary according to the specificneeds of each light source. For example, each light source may havedifferent light requirements (e.g., colors, durations, etc.) andtherefore the GUI may need to be modified.

FIGS. 6A and 6B are light distribution plots 300 and 302, respectively,that may be used to control the light intensity of a light sourceassociated with a component of a computer system, in accordance with oneembodiment of the invention. By way of example, the light distributionplots 300 and 302 may correspond to the data tables or formulasdescribed in FIG. 3. In FIG. 6A, the light distribution plot 300 is usedto control the light intensity of a light source associated with akeyboard. In FIG. 6B, the light distribution plot 302 is used to controlthe light intensity of a light source associated with a display (LCD).In both Figures, the light distribution plots 300 and 302 illustratecurves 304 showing light intensity as a function of ambient light level.The light intensity is on the vertical axis and ambient light level ison the horizontal axis. Referring first to the vertical axis, each ofthe curves 304 starts at a minimum light intensity 306 (shown by thedotted line) or greater and extends to a maximum light intensity 308.The minimum light intensity 306 generally corresponds to the minimumamount of light needed for viewing and the maximum light intensity 308generally corresponds to the maximum amount of light that may beproduced.

In a similar manner and referring to the horizontal axis, each of thecurves 304 also starts at a minimum ambient light level 310 or greaterand extends to a maximum ambient light level 312. The minimum ambientlight level 310 generally corresponds to complete darkness. The maximumambient light level 312, on the other hand, may correspond to manythings including the saturation point of the light sensors or the pointwhere light is needed for viewing. For example, in FIG. 6A, the maximumambient light level 312 may correspond to the point where backlightingis needed to help a user view the keys of the keyboard, i.e., when theambient light gets low (darker). By way of example, the maximum ambientlight level for backlighting may be between 0 and 10 lux, and moreparticularly about 5 to about 10 lux. In order to prevent thebacklighting from going on and off at a particular ambient level, ahysteresis loop 314 may be provided. The hysteresis loop 314 includes anactivation point 316 and a deactivation point 318. The deactivationpoint 318 represents the point where the backlighting is turned off andthe activation point 316 represents the point where the backlighting isturned on. In FIG. 6B, the maximum ambient light level 312 maycorrespond to the saturation point of the light sensors, i.e., at itscapacity. By way of example, the maximum ambient light level for thedisplay may be about 1000 lux. When each of the curves reaches thispoint they level off and maintain a constant light intensity even if theambient light level is higher.

Referring back to both Figures, each curve 304 represents a differentlevel of brightness. In most cases, a default curve 304′ (shown in bold)is present somewhere in between the other curves. The default curve 304represents the most likely curve for all conditions and users. Thecurves 304A located above the default curve 304 represent higherbrightness levels to varying degrees and the curves 304B below thedefault curve 304 represent lower brightness values to varying degrees.For ease of discussion, the different curves vary from 0 to +3 and from0 to −4 brightness units in increments of 1. This, however, is not arequirement since the levels may extend to a greater number of positiveor negative values. In most cases, the level of brightness is chosen bya user as for example using the GUI interface shown in FIG. 5. Forexample, a user may desire a greater amount of brightness therebyselecting the curves labeled +1, +2, or +3 or a user may desire a lesseramount of brightness thereby selecting the curves labeled −1, −2, −3 or−4.

FIG. 6C is a light distribution plot 330 that may be used to control thelight intensity of a light source associated with a sleep indicator, inaccordance with one embodiment of the invention. By way of example, thelight distribution plot 330 may correspond to the data tables orformulas described in FIG. 3. The light distribution plot 330illustrates curves 332 showing light intensity as a function of time forvarying levels of ambient light. The light intensity is on the verticalaxis and the time is on the horizontal axis. As shown, the curves 332follow a somewhat repeating waveform with peaks and troughs. As shouldbe appreciated, the light intensity of sleep indicators is generallydesigned to fade in and out between a minimum and maximum value so as toindicate that the computer system is in a sleep mode. Each curve 332represents a different level of ambient light. For ease of discussion,only three curves are shown (although many more curves can be used inactual practice). A first curve 332A is configured to represent a highambient light level, a second curve 332B is configured to represent anaverage ambient light level, and a third curve 332Cis configured torepresent a low ambient light level. By way of example, the low ambientlight level may correspond to about 0 to about 10 lux, the high ambientlight level may correspond to about 1000 lux, and the average ambientlight level is somewhere in between these two values.

With regards to FIGS. 6A-C, the curves themselves may be widely varied.For example, the slopes may be smaller or greater than shown.Furthermore, the curves may be curvilinear rather than rectilinear asshown. Moreover, it should be noted that maximum and minimum values,i.e., when the intensity is high or low or when the ambient light levelis high and low, tend to vary according to the specific conditions inwhich the lights are used. For example, what is considered low ambientlight with regards to the display may be different than what isconsidered low ambient light with regards to the indicator or keyboard(or vice versa).

FIG. 7 is a perspective diagram of a notebook computer 350, inaccordance with one embodiment of the invention. By way of example, thenotebook computer may correspond to the Powerbook manufactured by AppleInc. of Cupertino, Calif. The notebook computer 350 generally includes abase 352 and a lid 354, each of which has a housing that containsvarious internal components. With regards to the base 352, the internalcomponents may correspond to various integrated circuit chips and othercircuitry that provide computing operations for the notebook computer350. By way of example, the integrated circuit chips and other circuitrymay include processors, controllers, bridges, memory, circuit boards andthe like. The internal components can also take on other forms as forexample hard drives, fans, batteries, and the like. The base 352 mayalso include various I/O devices as for example a back lit keyboard 356,track pad 358, disk drive 360, speakers 362 and the like. The keyboardmay be a removable keyboard such as the keyboard described in U.S. Pat.No. 6,212,066, titled, “PORTABLE COMPUTER WITH REMOVABLE KEYBOARD,”issued Apr. 3, 2001, or U.S. patent application Ser. No. 09/755,625,titled, “KEYBOARD ARRANGEMENT,” filed Jan. 4, 2001 and that has issuedas U.S. Pat. No. 6,510,048, both of which are herein incorporated byreference. The base 352 may also include other circuitry includingconnectors 364, buttons 366, and indicators 368. The lid 354, on theother hand, typically contains a liquid crystal display (LCD) 370.

In most cases, the lid 354 is pivotally coupled to the base 352 via ahinge mechanism 372. As such, the lid 354 may rotate into an openposition (as shown) or a closed position (not shown) relative to thebase 352. As should be appreciated, the LCD display 370 is visible to auser of the notebook computer 350 when the lid 354 is in the openposition and no longer visible to the user when the lid 354 is in aclosed position. The notebook computer 350 may include a lockingmechanism 374 for securing the lid 354 to the base 352 when the lid 354is in the closed position. The locking mechanism 374 generally consistsof two parts, a base side locking mechanism 374A and a lid side lockingmechanism 374B. The base side locking mechanism 374A and the lid sidelocking mechanism 374B are cooperatively positioned so that when the lid354 is closed, the locking mechanisms 374 lockably engage with oneanother thus securing the lid 354 to the base 352. The locking mechanism374 also includes a knob, switch or button 376 for releasing the baseside locking mechanism 374A from the lid side locking mechanism 374B soas to allow the lid 354 to be opened. In the illustrated embodiment, theindicator 368 is disposed in the button 376. By way of example, theindicator 368 may be a sleep indicator that informs the user when theportable computer is in a sleep mode. An example of a locking mechanismthat may be used can be found in U.S. patent application Ser. No.09/755,622, titled, “LOCKING SYSTEM FOR A PORTABLE COMPUTER,” filed Jan.5, 2001 and that has issued as U.S. Pat. No. 6,659,516, which is hereinincorporated by reference.

In one embodiment, the notebook computer 350 includes a light adjustmentcircuit for adjusting the intensity of light outputted from the notebookcomputer 350. By adjusting the light intensity, the power consumption ofthe notebook computer 350 can be reduced thereby increasing batterylife. By way of example, the light adjustment circuit may correspond tothe circuit described in FIG. 2.

The light adjustment circuit generally contains various light sourcesconfigured to emit light as well as one or more light sensors configuredto measure the light level of the ambient light that surrounds thenotebook computer 350 during use. The configuration of the light sourcesand sensors of the light adjustment circuit may be widely varied. Forexample, the light sources and light sensors may be positioned almostanywhere on the notebook computer 350 (e.g., base or lid). Furthermore,the light sources and light sensors may be located at peripherallocations around the notebook computer (e.g., exposed) or they may belocated at internal locations within the notebook computer. In the latercase, windows and light conduits may be used to transmit ambient lightinto the portable computer or output light out of the notebook computer.

In one implementation, the ambient light receiving means whether a lightsensor, a window or a light conduit, is located on the mating surfacesof the base or lid. By mating surfaces, it is generally meant thesurfaces that mate when the notebook computer 350 is closed, as forexample, the surfaces that include the LCD 370 and keyboard 356. Whenlocated on the mating surfaces, the portable computer 350 can sense whenthe lid 354 is closed (e.g., no ambient light) and thus when thenotebook computer 350 is not in use. As a result, the notebook computer350 can reduce the intensity of the light for each of the light sourcesthereby saving valuable battery life.

In the illustrated embodiment, the light adjustment circuit includes afirst light source for lighting up the indicator 368 (e.g., LED), asecond light source for lighting up the back lit keyboard 356 (e.g.,LED) and a third light source for lighting up the LCD display 370 (e.g.,light panel). In one particular embodiment, the backlit keyboard isconfigured to illuminate the legends disposed on the keyboard so thatthey glow when the light source is turned on. When turned off, thelegends have a color that provides contrast with the rest of the key sothat they are clearly visible when the light source is turned off (andthe ambient light is high). In another embodiment, the backlit keyboardis configured to illuminate the area around the keys so as to define theedges of the keys. The light adjustment circuit also includes a pair oflight sensors 380, each of which is disposed within the base 352 of thenotebook computer 350, and more particularly behind a grill 382 of thespeakers 362 disposed in the base 352. As shown, the grill 382, whichincludes a plurality of holes, is typically formed in the housing thatforms the base 352. The holes act as a window or light conduit fortransmitting ambient light to the light sensors 380 disposed within thebase 382. As should be appreciated, the grill 382 is generally leftexposed during use so as not to muffle the sound emanating therefrom andthus it is a good location for positioning the light sensors 380, i.e.,typically not covered.

In one particular embodiment, the keyboard light comes on in low ambientlight, thereafter adjusts to the ambient light level and thenautomatically shuts off in brighter ambient light, i.e., the legendglows in dark conditions and reverts to its natural color in lightedconditions.

FIG. 8 is a side elevation view, in cross section, of a portablecomputer 400, in accordance with one embodiment of the presentinvention. By way of example, the portable computer 400 may correspondto the notebook computer shown in FIG. 7. The portable computer 400includes a housing 402 for enclosing a light sensor 404 that is attachedto a printed circuit board 406. The light sensor 404 may be attached tothe printed circuit board 406 using any suitable and conventional means.By way of example, the printed circuit board 406 may correspond to themother board of the portable computer 400. As shown, the housing 402includes a plurality of openings 408. The openings 408 are preferabledimensioned to allow the passage of ambient light 410 so that the lightsensor 404 can measure the intensity of the ambient light 410. By way ofexample, the openings 408 may form the grill of a speaker. In oneparticular implementation, the openings 408 have a diameter of about 0.8mm, and spacings therebetween of about 0.8 mm. Furthermore, the lightsensor 404 generally represents a photodiode as for example, thephotodiode BS520 manufactured by Sharp Microelectronics of America.

FIG. 9 is a side elevation view, in cross section, of a portablecomputer 420, in accordance with an alternate embodiment of the presentinvention. The portable computer 420 is like the portable computer 400shown in FIG. 7, however unlike the portable computer 400 shown in FIG.7, the portable computer 420 includes a light guide 422 configured tofocus the ambient light 410 onto the light sensor 404. The light guide422 is configured to receive the light 410 passing through the openings408 and to direct the light 410 to the light sensor 404. The lightincident on the light sensor 404 is thus more intense than wouldotherwise be achievable without the light guide 422.

FIG. 10 is a side elevation view, in cross section, of a portablecomputer 430, in accordance with an alternate embodiment of the presentinvention. The portable computer 430 is like the portable computer 400shown in FIG. 7, however unlike the portable computer 400 shown in FIG.7, the portable computer 430 includes a lens 432 configured to focus theambient light 410 onto the light sensor 404. The lens 432 is configuredto receive the ambient light 410 passing through the openings 408 and todirect it to the light sensor 404. The light incident on the lightsensor 404 is thus more intense than would otherwise be achievablewithout the lens 432.

FIG. 11 is a side elevation view, in cross section, of a portablecomputer 440, in accordance with an alternate embodiment of the presentinvention. By way of example, the portable computer 400 may correspondto the notebook computer shown in FIG. 7. In this particular embodiment,a light pipe 442 is configured to direct ambient light 410 from outsidethe housing 402 to inside the housing 402 towards the light sensor 404.The light pipe 442 may be integrally formed with a window 444 located ina wall of the housing 402 or it may be a separate component. In thelater case, the light pipe 442 may be configured to contact at least aportion of the window 444 or may include a gap therebetween. In asimilar vein, the light pipe 442 may be configured to contact at least aportion of the light sensor 404 or may include a gap therebetween.Furthermore, the light pipe 442 may be structurally coupled to thehousing 402 or it may be structurally coupled to the light sensor 404 orto the circuit board 406 to which the light sensor 404 is attached. Asshould be appreciated, the material that forms the light pipe 442 mustbe suitable to facilitate the transmission of light therethrough. Insome implementations, the material corresponds certain types of plasticsor other translucent materials.

FIG. 12 is a side elevation view, in cross section, of a portablecomputer 450, in accordance with an alternate embodiment of the presentinvention. The portable computer 450 is like the portable computer 440shown in FIG. 11, however unlike the portable computer 440 shown in FIG.10, the portable computer 450 includes one or more flexible light pipes452 configured to distribute light ambient light 410 to the light sensor404. Flexible light pipes typically allow a wider range of light sensorpositions. For example, the light pipe 452 may be used to distribute theambient light 410 to the light sensor 404 by bending around componentsdisposed therebetween (e.g., walls, frames, I/O devices and the like).The light pipe 452 generally includes a transmissive portion at itsinterior and a reflective portion at its exterior. Because the exteriorof the light pipe 452 is reflective (due to total internal reflection),the light 410 reflects off the sides of the pipe 452 as it travelsthrough the interior of the light pipe 452. Accordingly, when light 410is made incident on an inner edge 458 of the light pipe 452 it isdirected through the light pipe 452 via the transmissive and reflectiveportions to an outer edge 460 of the light pipe 452 where it emits thelight 410 to another location positioned away from the location of theoriginal ambient light 410.

FIG. 13 is a side elevation view, in cross section, of a back litkeyboard 470, in accordance with one embodiment of the presentinvention. By way of example, the back lit keyboard 470 may generallycorrespond to the back lit keyboard shown in FIG. 7. The keyboard 470 isconfigured to allow a user to input commands and other instructions to aportable computer 472. For example, the keyboard 470 may allow a user ofthe portable computer 472 to enter alphanumeric data or to execute taskssuch as GUI selections. As shown, the keyboard 470 includes a pluralityof keys 474 that are attached to a base plate 476. The keys 474 may beattached using any suitable arrangement. In the illustrated embodiment,the keys 474 are attached via a linkage 478 that allows the keys 474 tomove up and down relative to the base plate 476. By way of example, thelinkage 478 may be a scissor mechanism. Although not shown, the baseplate 476 generally includes a circuit layer that sends a signal to theportable computer 472 when a particular key 474 is pressed down. Thebase plate 476 may also include a spring element (not shown) for biasingthe keys 474 in the up position. Furthermore, the keyboard 470 ispositioned within an opening 477 of a base 478 of the portable computer472. The keyboard 470 may be held within the opening 477 using anysuitable means (e.g., screws, bolts, etc.). In one embodiment, thekeyboard 470 is removable so latches, hooks, snaps, magnets, and thelike may be used to hold the keyboard 470 relative to the base 478.

As shown, a light source 480 is disposed underneath the base plate 476.The light source 480 is configured to provide light to the keyboard 470so that the keyboard 470 can be illuminated. The illumination may bewidely varied. The illumination may be provided in the space between thekeys 474 so as to better define the edge of keys 474. Alternatively oradditionally, the illumination may be provided through the keys 474 soas to better define the keys 474. In one embodiment, the legend 482(e.g., letter or symbol) disposed on the keys 474 is illuminated ratherthan the entire key 474. The base plate 476 is generally configured withone or more openings 484 so as to deliver the light from the lightsource 480 to the keys 474. In essence, the openings 484 allow lightemanating from the light source 480 to travel to and/or around the keys474, i.e., the light that passes through the opening 484 may be used toilluminate the space between the keys 474 and/or the keys 474themselves.

Alternatively or additionally, the base plate or portions thereof may beformed from a translucent material thereby allowing the light to betransmitted therethrough. The light source may be widely varied. Forexample, the light source may be one or more light panels, a pluralityof spaced apart light sources, and the like that directs light towardsthe backside of the base plate. In the illustrated embodiment, the lightsource 480 corresponds to a light panel that distributes light over anarea. For example, it may be configured to distribute light towards theentire backside of the base plate 476 or it may distribute light to onlya portion of the base plate 476. Moreover, the light source 480 may beconfigured to contact at least a portion of the base plate 476 or it mayinclude a gap therebetween (as shown).

FIG. 14 is an exploded perspective view of a back lit keyboard 500, inaccordance with one embodiment of the present invention. By way ofexample, the back lit keyboard 500 may generally correspond to thekeyboard shown in FIG. 13. In this particular embodiment, the back litkeyboard 500 consists of a keyboard 502 and a light panel 504. Thekeyboard 502 is configured to transmit light from the backside of thekeyboard 502 where the light panel 504 is located to the opposite sidewhere the keys 506 of the keyboard 502 are located. In one embodiment,the legends located on the keys 506 as well as the spaces locatedbetween the keys 506 are illuminated. As such, the keyboard 500 includesa path for distributing the light to the keys 506 as well as to thespaces 508 between the keys 506.

As shown, the light panel 504 includes a plurality of optical fibers510. The optical fibers 510 are generally configured to allow lightpassing therethrough to escape through the outer surface of the opticalfiber 510. By way of example, the optical fibers may be scored atvarious locations along the length so that the light leaks out of theoptical fiber. Furthermore, the optical fibers 510 are positionedadjacent one another in rows so as to form a sheet of optical fibers.The optical fibers 510 thus distribute light in a planar manner. In somecases, the optical fibers 510 are attached to a backing sheet 512 tohelp hold them together. The backing sheet 512 may also help direct thelight in direction of the keyboard 502, i.e., it may be a reflectivesurface that helps direct the light to one side of the light panel 504.Furthermore, each of the optical fibers 510 are optically coupled to alight source 514. For example, the ends of the optical fibers 510 may bepositioned adjacent a light source 514 so that the light emanating fromthe light source 514 passes therethrough. By way of example, the lightsource may correspond to a light emitting diode (LED). In theillustrated embodiment, each of the optical fibers 510 extends into alight housing 516 that contains the light source 514. The light housings516 provide a means for connecting the ends of the optical fibers 510proximate the light source 514 and they may help direct light from thelight source 514 into the optical fibers 510. In some cases, a cover 518may be provided to protect the proximal portions of the optical fibers510 as well as the light housing/light sources 514/516. By way ofexample, the light panel described above may be manufactured byPoly-Optical of Irvine, Calif.

The configuration of the light panel 504 may be widely varied. In theillustrated embodiment, the light panel 504 is broken up into aplurality of strands 520, each of which includes a plurality of opticalfibers 510. The optical fibers 510 from each strand may extend into asingle light housing/light source 514/516or they may extend intomultiple light housing/light sources 514/516 (as shown). Each of thestrands 520 is separated by a gap 522. The gap 522 may allow space forfibers and other components that need to pass through the light panel504. The multiple edges of the strands 520 may also be used to helpsecure the light panel 504 to the back of the keyboard 502. For example,the edges may be secured to the backside of the keyboard 502 with screwsthat trap the edge of the strands 520 between the screw and the backsideof the keyboard 502. The number of strands 520 may be widely varied. Inone embodiment, the number of strands corresponds to the number of rowsof keys on the keyboard 502, i.e., for every row of keys there is acorresponding strand. This, however, is not a requirement as the numberof strands may depend on other factors.

The light source 514 may be configured to distribute white or coloredlight. In some circumstances, the light source 514 itself is capable ofproducing different colors and in other cases different colored lightsources 514 may be optically coupled to different optical fibers 510from each strand 520 so that the color of light emanating from eachstrand 520 can be controlled. By way of example, the light panel 504 maybe configured to change its color in a manner similar to that which isdisclosed in. U.S. patent application Ser. No. 10/075,964, titled,“ACTIVE ENCLOSURE FOR COMPUTING DEVICE,” filed Feb. 13, 2002 andpublished as Publication No. 2003/0002246, and U.S. patent applicationSer. No. 10/075,520, titled, “COMPUTING DEVICE WITH DYNAMIC ORNAMENTALAPPEARANCE,” filed Feb. 13, 2002 and issued as U.S. Pat. No. 7,113,196,both of which are herein incorporated by reference.

FIG. 15 is a broken away side elevation view, in cross section, of aback lit keyboard 550, in accordance with one embodiment of the presentinvention. By way of example, the back lit keyboard 550 may generallycorrespond to the back lit keyboard shown in FIG. 13. The back litkeyboard 550 generally includes a plurality of keys 552, each of whichis movably mounted to a base plate 554 via a scissor mechanism 556. Thescissor mechanism 556 provides stability to the keys 552 while allowingthe keys 552 to move up and down. The keys 552 and the base plate 554are both composed of various layers. The keys 552 include a translucentbase layer 558 and an opaque mask layer 560. The base layer 558 isconfigured to allow the passage of light therethrough. The mask layer560, on the other hand, is configured to cover the base layer 558 exceptat an opening 562. Light is therefore allowed to pass through the baselayer 558 and out the opening 562 in the mask layer 560. The opening 562generally defines a legend on the keys 552. By way of example, thelegend may correspond to letters, symbols and the like. The base layer558 and the mask layer 560 may be widely varied. In one embodiment, themask layer 560 is painted (e.g., primer and color coat) on the baselayer 558, which is formed from clear or translucent plastic, and thenthe mask layer 560 is laser etched to form the opening 562. In somecases, the base layer 558 is also etched so as to produce a frostedsurface. The frosted surface produces a uniform glow when the keys 552are illuminated with light.

The base plate 554 includes a feature plate 568, a switch membrane 570,a rubber dome sheet 572 and a mask layer 574. The feature plate 568 isconfigured to support the various layers of the keyboard 550 in theirassembled position. The feature plate 568 includes an opening 576underneath each of the keys 552. The openings 576 provide an area wherelight may pass so as to illuminate the rest of the keyboard 500. Thebase plate 554 may include a transparent disk 578 disposed in theopening 576 of the feature plate 568. The transparent disk 578 isattached to the back of the switch membrane 570 and may be trappedbetween portions of the feature plate 568 and the switch membrane 570.The transparent disk 578 is configured to provide rigidity at theopening 576 so as to prevent bowing in areas surrounding the opening 576when the key 552 is pressed down while still allowing the passage oflight. Although not shown in great detail, the scissor mechanism 556 istypically attached to the feature plate 568. The feature plate may beformed from sheet metal such as stainless steel.

The switch membrane 570, which is positioned over the feature plate 568,carries the circuit switches used to drive the signals when the keys 552are pressed down. The switch membrane 570 generally includes a flexibleand translucent sheet with a circuit pattern formed thereon. Thetranslucency of the sheet is configured to allow the passage of lighttherethrough. The switch membrane 570 typically includes a through hole580 for the scissor mechanism 556. In some cases, the switch membrane570 may include a mask layer for preventing the passage of lighttherethrough although this is not a requirement.

The rubber dome sheet 572, which is positioned over the switch membrane570, carries a plurality of rubber domes 582 that provide a biasingforce to each of the keys 552, i.e., they bias the keys upward. The usertherefore must work against the biasing force (by pressing down on thekey) in order to actuate the switch on the switch membrane 570. Therubber dome sheet 572 is also formed from a translucent material so thatlight may pass therethrough. Like the switch membrane, the rubber dome572 sheet also includes a through hole 584 for the scissor mechanism556.

The mask layer 574, which is positioned over the rubber dome sheet 572,covers the rubber dome sheet 572 except at an opening 586. Light istherefore allowed to pass through the other layers and out the opening586 in the mask layer 574. In most cases, the mask layer 574 covers theareas of the base plate 554 between adjacent keys 552 thereby providinga uniform look between adjacent keys 552. In the illustrated embodiment,the mask layer 574 starts at a point underneath the key 552. The masklayer 574 may work with the mask layer of the switch membrane 570 tomask the desired portions of the base plate 554. In most cases, the masklayer 574 is printed on the surface of the rubber dome sheet 572. Themask layer 574 may be any color. In one particular implementation, themask layer is gray.

The back lit keyboard 550 also includes a light panel 590. The lightpanel 590 is disposed underneath the base plate 554 so as to illuminatethe keyboard 550. The light panel 590 may or may not be attached to thebase plate 554. In the illustrated embodiment, the light panel 590 isattached as for example using screws or bolts. As discussed previously,the light panel 590 generally includes a plurality of optical fibers 592and a backing sheet 594. The optical fibers 592 are typically formedfrom a clear material. In one implementation, one end of the opticalfibers are connected to an LED and the opposite end is blocked.Moreover, the optical fibers are lined up in a sheet and scored (cut) sothat light may leak therefrom, i.e., along the body of the fiber threadrather than only at its ends. By way of example, the optical fibers mayhave a diameter of about 0.1 inches. The optical fibers 592 aregenerally attached to the backing sheet 594 via an adhesive 596 such asglue. The backing sheet 594 helps to maintain the position of theoptical fibers 592 and to direct the light emanating from the opticalfibers 592 towards the back side of the base plate 554.

As shown in FIG. 15, the light panel 590 transmits light towards theback side of the feature plate 568. Light that intersects the featureplate 568 is blocked while light that intersects the opening 576 isallowed to continue on its path. The light traveling through the opening576 in turn passes through the transparent disk 578, the switch membrane570 and the rubber dome sheet 572. Thereafter, the light eitherintersects the mask layer 574 or the opening 586 in the mask layer 574.Like the feature plate 568, light that intersects the mask layer 574 isblocked while light that intersects the opening 586 is allowed tocontinue on its path. The light exiting the opening 586 in turn lightsup the area between the keys 552 and the base plate 554. Some of thelight illuminates the keys 552 and some of the light illuminates thearea between adjacent keys 552. For example, some of the light passesthrough the base layer 558 of the key 552. This light either intersectsthe mask layer 560 or the opening 562 in the mask layer 560. The lightthat intersects the mask layer 560 is blocked while light thatintersects the opening 562 is allowed to continue on its path. In mostcases, the light exiting the opening 562 is diffused in some manner soas to produce a uniform glow at the top surface of the key 552. Some ofthe light also passes through the gap formed between the key 552 and thebase plate 554. This light typically reflects off the top surface of themask layer 574 thereby illuminating the area between adjacent keys 552.

FIG. 16 is a top view, in cross section, of a portable computer 600, inaccordance with one embodiment of the present invention. By way ofexample, the portable computer 600 may correspond to the portablecomputer shown in FIG. 7. The portable computer 600 includes a housing602 having a button 604 attached thereto. The button 604 is configuredto move through a hole 606 in the housing 602 in order to actuate somefeature of the portable computer 600. For example, the button 604 may beused to release a locking mechanism that locks the lid to the base ofthe portable computer 600. The housing 602 itself is configured toenclose internal components of the portable computer 600. In theillustrated embodiment, the housing 602 encloses at least an indicatorarrangement 608 for alerting the user when a computer event occurs. Forexample, the indicator arrangement 608 may be a used to indicate thatthe portable computer 600 is in a sleep mode. As shown, the indicatorarrangement includes a light source 610, a light pipe 612, and a window614. The light source 610, which is attached to a printed circuit board616, is configured to emit light inside the housing 602. The light pipe612, which is also attached to the printed circuit board 616, isconfigured to direct light from the light source 610 to the window 614.The window 614, which is incorporated within the button 604, isconfigured to allow the passage of light therethrough so as to allowlight emanating from the light source 610, and more particularly lightexiting the light pipe 612, to travel outside the housing 602, and moreparticularly the button 604. In most cases, the light exiting the window614 is diffused in some manner so as to produce a uniform glow at thesurface of the window 614.

As should be appreciated, the material that forms the light pipe 612 andwindow 614 must be suitable to facilitate the transmission of lighttherethrough. In some implementations, the material corresponds certaintypes of plastics or other translucent materials. In one particularimplementation, the light pipe 612 includes a light receiving surface620 and a light output surface 622. The light receiving surface 620 isgenerally located proximate the light source 610 so as to collect lighttherefrom., and the light output surface 622 is generally directedtowards and proximate to the window 614 so as to transmit light thereto.The other surfaces of the light pipe 612 are typically reflective due tototal internal reflection and thus they tend to concentrate lightthrough the light output surface 622. Furthermore, the light source 610may be selected from any suitable light emitting device. In theillustrated embodiment, the light source 610 corresponds to a sidefiring light emitting diode that directs light generally in onedirection, as for example, the direction of the light receiving surface620 of the light pipe 612.

The light pipe 612 may be configured to contact at least a portion ofthe window 614 or may include a gap therebetween. The later is generallypreferred so as not to obstruct the button 604 when it is moved inward.Alternatively, the light pipe 612 may be integrally formed with thewindow 614 thereby moving with the button 604. In a similar vein, thelight pipe 612 may be configured to contact at least a portion of thelight source 610 or may include a gap therebetween.

It should be noted that the above configuration is not a limitation andthat the indicator arrangement may vary according to the specific needsof each portable computer. For example, the window 614 may be located ina wall of the housing rather than the button. Furthermore, the lightguide 612 may be attached to the housing 602 rather than to the circuitboard 616.

While this invention has been described in terms of several preferredembodiments, there are alterations, permutations, and equivalents, whichfall within the scope of this invention. For example, although theinvention was described primarily in terms of a notebook computer, itshould be noted that this is not a limitation and that the invention canbe implemented in other computing devices and more particularly otherconsumer electronic products. That is, it is contemplated that thepresent invention, whether completely or in part, may be adapted for anyof a number of suitable and known computing devices or consumerelectronic products that perform useful functions via electroniccomponents (e.g., audio, video, computing, etc.). By way of example, thepresent invention may be incorporated into general purpose computerssuch as desktop computers that sit on desks, floors or other surfaces(both segmented and all-in-one machines), portable or handheld devicessuch as personal digital assistants (PDAs), mobile phones, media players(MP3 players), cameras (both video and photos) and the like.

It should also be noted that there are many alternative ways ofimplementing the methods and apparatuses of the present invention. Forexample, although the ambient light level range was given as 0 to 1000lux, it should be noted that this is not a limitation and that it mayextend above this range. It is therefore intended that the followingappended claims be interpreted as including all such alterations,permutations, and equivalents as fall within the true spirit and scopeof the present invention.

What is claimed is:
 1. A handheld electronic device, comprising: a lightsource; a light sensor; a light controller configured to process lightinformation associated with the light sensor and the light source; ahousing that encloses the light source, the light sensor, and the lightcontroller, wherein the housing includes a plurality of openings andwherein the light sensor is configured to receive light through theplurality of openings; and an output device that conveys signals to auser through the plurality of openings.
 2. The handheld electronicdevice defined in claim 1 wherein the light source comprises a portionof a display.
 3. The handheld electronic device defined in claim 2wherein the display comprises a liquid crystal display.
 4. The handheldelectronic device defined in claim 3 wherein the portion of the displaycomprises a light panel of the display.
 5. The handheld electronicdevice defined in claim 1 wherein the light sensor comprises an ambientlight sensor.
 6. The handheld electronic device defined in claim 5,further comprising an additional ambient light sensor.
 7. The handheldelectronic device defined in claim 1, further comprising storageconfigured to store an illumination profile that defines a relationshipbetween measured ambient light levels and light intensities of the lightsource.
 8. The handheld electronic device defined in claim 7 wherein thelight controller is configured to control the light source using thestored illumination profile.
 9. The handheld electronic device definedin claim 8 wherein the stored illumination profile comprises a datatable that includes the ambient light levels as inputs and the lightintensities as outputs.
 10. A mobile phone, comprising: a light source;an ambient light sensor; a housing that surrounds the light source andthe ambient light sensor, wherein the housing includes at least onespeaker opening and wherein the ambient light sensor is configured toreceive ambient light through the at least one speaker opening; and aprocessor, wherein the processor is configured to process measuredoutput from the ambient light sensor and light instructions for thelight source.
 11. The mobile phone defined in claim 10 wherein theprocessor is further configured to control an intensity of the lightsource based on the measured output from the ambient light sensor. 12.The mobile phone defined in claim 11 wherein the light source comprisesa light source associated with a display.
 13. The mobile phone definedin claim 12 wherein an intensity of light emitted by the display isbased on the measured output from the ambient light sensor.
 14. Themobile phone defined in claim 13 wherein the display includes liquidcrystal cells.
 15. The mobile phone defined in claim 14 wherein thedisplay further comprises at least one polarizing filter.
 16. The mobilephone defined in claim 14 wherein the display further comprises a glassplate.
 17. The mobile phone defined in claim 12, further comprising anadditional ambient light sensor that receives ambient light through thematerial.
 18. A media player, comprising: a processor; a light source; alight sensor; a light controller coupled to the processor and configuredto direct light information between the processor, the light sensor, andthe light source; and a housing that encloses the processor, the lightsource, the ambient light sensor, and the light controller, wherein thehousing includes a plurality of speaker openings and wherein the ambientlight sensor is configured to receive light through the plurality ofspeaker openings.